Hydraulic system, including multiple motors and controls therefor



L O R T N O C D N A S R O T O M E L P T. T mw M G N I D U L C N I M E TS Y S .C I L U A. R w. un

Nov. 4, 1952 B. F. QulNTlLlAN 7 4. 9 1 5 l V l u J d e 1 .1 F

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wall of the casing around the vinlet opening for y closing off thisopening from communication with both of the outlet ports. The fluidreceiving chamber 22 preferably is suieiently large to dene a space withthe piston for communication between the two outlet ports when the inletport is closed as just described. In full retracted position, the pistonhead enters a reduced bore section 22a of the fluid receiving chamber22. A cylindrical portion 23h of the enlarged end or head of the pistonthere servesV to close o'i the outlet port 25 While leaving inlet portopen to outlet port 26. In intermediate positions of the enlarged pistonend, between the opposite ends of chamber 22, the inlet portconveniently is open to both outlet ports. Y

The control valve preferably includes a pressure relief valve 30 as aunitary part thereof for relieving fluid pressure in excess of a certainamount. I usually build this relief valve into the control piston 23.Where this is done the piston illustratively has an orifice 30a in thetapered end portion 23a thereof, an enlarged axial b-ore 30h-forreceiving iiuid` through the orice, and a ball check 3|lc normallyseating over the orifice from within the bore. A coil spring 30dcompressed in the bore 3'Ilbrbetween the ball and the innermost end ofthe bore serves vto maintain closure of the orifice up to a certaincounteracting fluid pressure. 'I'he relief valve also has an outlet port38e which empties into chamber 22 of the control valve and into outletport Vas will be more fully explained hereinafter.

With particular reference again to the embodiment of my multiple motorhydraulic control system represented in vFigure 1, it will be seen thatthe aiding parallel branch circuit includes fluid pump I2, conduit I4 tojunction 41, fluid line 48 leading from this junction to inlet'2I of themotor control valve 20, conduit I9 interconnecting outlet 26 of thecontrol valve and inletside of the aiding motor II, fluid exhaust lines42 and 44 extending from the motor outlet to the junction 2|, conduit I5to the reservoir I6, and conduit I8 back to the pump. A lin-e 45 forbypassing fluid around both of the hydraulic motors I U and II leadsfrom outlet 25 of the control valve to junction 43 with exhaust line 44.Y y

With the piston 23 of the control valve set to the position indi-catedin Figure 1 of the drawing, the inlet port 2| of the valve is closed.The hydraulic pump I2 during operation then draws fluid from thereservoir I6 and supplies this fluid A rotation thus is imparted to therotor of this motor and the related shaft I3. Fluid exhausts from themotor through conduit l5 back to the reservoir. The iiuid pressuredeveloped during this time on the inlet side of themotor is transmittedthrough line 48 to the closed inlet port 2I of the control valve. Shouldthe pressure become excessive, such as by attaining a value beyonddesired limits of operation of the system, the relief valve is opened,ball check 30e lifting and thus admitune Huid. through prima 30a, here,3012.., Outlet 4 port 30e and chamber 22. A substantial quantity of thisiiuid then escapes through outlet port 25. bypass line and exhaust line44, to conduit I5 at junction 2I, and through conduit I5 back to thereservoir I6, thus circumventing the motor I0. This escape continuesuntil certain operatinglpressures in the system are resumed, at which.time the relief valve 30 again closes'a'nd is held closed by the coilspring 30d acting on ball check 30o.

When the mot-or I Il alone is exposed to the energizing effect offluidsupplied from the pump 'I2,' in the'manner described, shaft I3 serves-to Arotate the rotor of motor II.

y The idling motor II therefore tends to function as a, pump to theextent of its displacement. Thus, to avoid the development of a vacuumas on the valve 2n in View of thisl pumping action, I rely upon a iiuidthe ball check 30o, this pressure recirculation circuit, including themotor II, the motor exhaust line 44, `line 45, outlet port 25 of thecontrol valve, chamber 22, outlet port 26, and conduitle leading back tothe motor. Fluid pumped by the motor, accordingly, passes at lowpressure through this circuit without impairment or injury yto thesystem. At times, I nd advantage in employing an over-running clutch 50between thejshaft I3 and the rotor of motor II for disconnecting theshaft and rotor when the motor I 0 alone is operating.

By displacing the piston 23 of the control valve to a position such asrepresented in Figure 2, thereby closing the outlet port 25 and puttingthe inlet port 2I and outlet port 26 in open communication, theaiding'motor II comes into operation, this while the motor IIJ continuesoperation. Where the pump I2 is a constant delivery pump, the samequantity 'of uid continues to come Vinto the system as compared withthat in single motor operation. Fluid for producing the aiding motorfunction is pumped from the reservoir I 6 through conduit I8 by the pumpI2 and then is supplied through conduit I4 to junction 41, thencethrough uid line 48, inlet port 2Iv of the control valve, fluidreceiving chamber 22 of this valve, outlet port 26, through conduit I9and the aiding motor 'I I,iiuid exhaustvline 42 vto junction 43, exhaustline 44 to vjunction 2'I, Yand thence through conduit I5 back to thereservoir. In the instance of high-torque low-speed operation of themotor II, the driven shaft I 3 receives the additional torque,Which'serves to supplement the output of the motor III. Should pressurein the system exceed the seating pressure of the coil spring 30d on isrelieved by the relief valve 30. The relief is effected by fluid passingthrough orifice 30a,bore 30h and outlet port 30e, and to outlet port 25in the control valve casing. vThe fluid then exhausts through lines 45,444 and I5, respectively, back to the reservoir I6, thus bypassing bothmotors. This bypassing action maintains until a suiiiciently lowpressure is resumed in the system, at which time the. reliefvalve 30closes. Both motors continue their coupled driving eifect on the shaftI3 until the piston 23 is reset to close the inlet port 2I as forresuming high-speed low-torque operation of the motor I0.

The high and low speed motor control positions of lthe piston 23 of thecontrol valve 20 are conveniently achieved with theaid of suitablemanual setting means, or by suitable automatic means for giving asetting of the piston consistent with the motor load. In positions ofthe piston between those giving single motor operation and multiplemotor operation, uid admitted through inlet `cpeiling 2 I to chamber 22and outlet opening 25, causes a sufllcient drop in pressure in theentire hydraulic system for stopping either or both motors.

Thus it will be seen that in this invention there are provided amultiple motor control system and control valve in which the variousobjects noted herein together with many thoroughly practical advantagesare successfully achieved. It will be seen that the system is wellsuited for operating under load and for achieving single or multiplemotor operation consistent with varying power demands. It will beobserved also that the control valve is simple, compact and capable ofgiving highly satisfactory control over a plu- -rality of iiuid motorsand enables the selective operation of one of these motors to theexclusion of another.

As many possible embodiments may be made of my invention and as manychanges may be made in the embodiment hereinbefore set forth, it will beunderstood that all matter described and illustrated herein is to beinterpreted as illustrative and not as a limitation.

I claim:

l. A multiple motor control system, comprising in combination, a sourceof pressure fluid supply including a reservoir, at least two fluidmotors connected in aiding mechanical relation with each other, a fluidcircuit directly connecting one of said motors with said source ofsupply, a parallel fluid circuit connecting another of said motors withsaid source of supply, and a fluid control valve having a chamber withan inlet and two outlets connected in said parallel circuit, one outletleading to said other motor and the other outlet leading to saidreservoir, said valve having movable piston means in said chamber forselectively sealing 01T said inlet port ir 1 one position thereof andsaid other outlet port in another position and While in the inlet portclosing position admitting intercommunication of said outlet ports, saidpiston means including an axial bore with spring seating valve meansforming a pressure relief valve for spilling off fluid through the otherone of said control valve outlets for said two iluid motors when thepiston means is in either of the selected positions.

2. A fluid control valve comprising in combination, a casing having afluid receiving chamber and an inlet port and a plurality of outletports for the chamber, and a uid control piston in said chamber forselectively sealing off said inlet port in one position thereof and oneof said outlet ports in another position, and While in the inlet portclosing position admitting intercommunication of said outlet ports, saidpiston including an axial bore with oriiice therein in continualcommunication with said inlet port, a ball check received in said axialbore, a spring also received in said bore and maintaining said ball toclose said orice, and an outletl from said bore to effectpressure-responsive relief for said valve in either of the selectedpiston positions.

3. A fluid control valve comprising in combination, a casing havingafiuid receiving chamber and an inlet port and a plurality of outletports therein for the chamber, and a uid control piston in said chamberfor selectively sealing off said inlet port in one position thereof andone of said outlet ports in another position, and while in the inletclosing position forming a space with said casing wall communicatingwith said outlet ports, said fluid control piston including an axialbore with spring seating valve means therein for relieving fluidexceeding a predetermined pressure value in either of the selectedpositions of the piston and having an outlet emptying from said axialbore into the selective outlet port in the casing.

BARTHOLOMEW F. QUINIILIAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 12,966 :Stoddart May 29, 1855382,643 Fox May 8, 1888 807,269 Hildebrand Dec. 12, 1905 965,052Wainwright July 19, 1910 1,055,619 Dunn Mar. 11, 1913 1,156,816 RichOct. 12, 1915 1,349,924 Swanson Aug. 17, 1920 1,972,821 WeatherheadSept. 4, 1934 2,023,524 Heaton Dec. 10, 1935 2,056,910 Schauer Oct. 6,1936 2,337,499 Roth Dec. 21, 1943 2,370,526 Doran Feb. 27, 19452,374,588 Doran Apr. 24, 1945 FOREIGN PATENTS Number Country Date 64,014Germany June 12, 1892 421,296 Germany Nov. 9, 1925 582,879 France Oct.22, 1924

